Electromotor



E. E. GREGORY ET AL R 21,579

Sept. 24, 1940.

.ELEC'IROM OTOR Original Filed July 1, 1930 2 Sheets-Sheet 1 rilllllll4 ivllilliilll'l n4!!! T M N 0 w W9C mm 4 v n N m m 2 E. E. GREGORY ET AL Sept. 24, 1940.

ELECTROMOTOR Original Filed July 1, 1930 2 Sheets-Sheet 2 INVENTORS E. E. GREGORY gym Heron/was, firm; 17M THEIR ATTORNEYS Reissued Sept. 24, 1940 UNITED STATES .ItIiEGregor Sth-HngJtL ndHenryEmci-Ion- N. I; said Comings assignortosaidGregol-y Original 1%. 1393.025. dated January 3.1933, se-' rlai No. 485,150, July 1, 193..

Application for rei-ue August 17, 1939, Serial No. 290,710

This invention relates to electromotors .oi the kind adapted to produce an oscillating motion. The invention aims to provide an electromotor of improved construction which in its main fea-' tures is adaptable for technical or industrial use such for example as the operation of signals and relays.

One -of the important uses for such motors, however, is in actuating changeable exhibitors or' animated advertising devices, and the invention will therefore be described particularly as applied to the operation of such devices. As to its details, moreover, the invention is directed to the adaptation of our improved electromotor to this use.

- Animated advertising devices, such for example as display posters, are employed quite widely in window advertising where the impartation of motion to one or more of the elements making up the scene on the poster attracts attention to the poster and the entire window. The display poster presents to the advertiser an almost limitless number of possibilities for an'anging scenes of which the advertising value can be greatly increased by imparting an oscillating motion to one of their elements. Although a number of elements of the scene on the poster may be animated ifdesired, it is usually sufllcient to animate a single one.

Accordingly the objects of our invention are, v

readily remove theelectromotor'from an advertising device which he desires to discard and apply it to a new device.

Third, to provide an electromotor for actuating advertising devices which is capable of producing an extremely long oscillating stroke but which is also readily adJustable to vary the length of the stroke, and also to a certain extent to vary the kind or type of motion produced.

Fourth, to adapt an electromotor to the actuation of adverlsing devices in such a way that nections of Fig; 1.

' by meansvof a solenoid or electromagnetic coil '7, or the movablearm 24 of the blacksmith and anvil posterahowninFlg. 8.

the element of the scene which is to be actuated by the device can be readily adjusted both-angularly and radially to suit the other parts of the relates to several embodiments-of the invention.

In these drawings:

Fig. 1 is a view 0! our electromotor in elevation looking at the rear of an advertising poster on which it is mounted.

Fig. his a diagram showing the circuit con- Fig. 2 is a similar view looking at the front of the poster and showing the arm for supporting the element of the scene on the poster which is to be moved by the electromotor. Fig. 3 is a vertical section taken on line 3-4 of Fig.1.

Fig. 4 is a perspective view showing the suppo ng arm in detail.

5 is a side view of the shaft of the motor. Fig. 6 is a perspective view showing the manner in which a moving element of the scene, a semaphore for example, is attached to the supporting arm of Fig. 4. Fig. 7 is a front view of a fragment of a poster showing a slightly'diflerent form of semaphore actuated by the electromotor.

Fig. 8 is a similar view of a fragment of a different poster. I Fig. 9 is a view similar to Fig-1 of a modified form of electromotor.

Fig. 10 -is a horizontal section taken on ,line ll-IO of Fig. 9.

Fig. 11 is a view 'also similar to Fig. 1-0! a still further modified form of electromotor, and

Fig. 12 is a section taken on line l2--l2 of Fig. 11.

Referring now to the accompanying drawings, our improved electromotor comprises an oscillater 2. adapted to be set in oscillating motion 2! in a manner to be presently described, and to impart this motion to the supporting arm 22 which may carry for example the semaphore II which is an element of the. poster shown in Fig.

The various parts of the mechanism of the electromotor are supported upon the sheet 25 of cardboard or other material comprising the poster by means of a threaded sleeve it which passes through an aperture in the poster and which is provided with outer and inner clamping nuts 21 andllrespectively. Awasherflmaybeplaced undertheouternutflisdesired.

The solenoid II is appropriately mounted upon the upper end of an arm II which extends radially from sleeve II and is frictionally held in pomtion by means of inner nut II, the arm 3. being apertured. for the v; e of sleeve 26. Arm II is preferably provided with an extension 3| projecting downwardly beyond the periphery of the oscillator 20 to partially counterbalance the weight of the coil 2| and to provide a convenient means of adjusting the angular position of solenoid II, which will be referred to later on. It also affords a convenient support for the electrical conductors I! by means of which current is supplied to the solenoid 2 I The electromotor shaft 33 is rotatably carried in a bushing 34 which is frictlonally retained in sleeve 28. By makingshaft 33 of extremely hard and highly polished material, such for example as piano wire, and employing a bushing 34 of oiled wood or fibre, or the like, a bearing is provided which will operate noiselessly and without lubrication for months before sufficient wear takes place to necessitate replacement of either the bushing or the shaft.

The outer end of shaft is is provided with an enlarged head 35 which is preferably knurled and over which the hub of the supporting arm 22' fits, the friction between these two parts being sufficient to maintain the arm in the desired angular position and at the same time allow it to be rotated to the position desired to suit the particular scene on the poster. Although various forms of arms 22 may be used, that shown in the drawings is particularly convenient because it is light in weight, cheap, easily and effectively attached to the head 35, and provides for the ready attachment and removal of themovable element of the scene.

This particular form of supporting arm 22 which we have devised is made entirely of resilient wire. The arm has two spring sections 31 and I8 formed by bending the wire upon itself attheouterendofthearm. 'Iliisproducesa smooth rounding point which will not catch or.

mar anything with which it comes in contact. Moreover, the arms 31 and 38 which spring outwardly away from each other are readily adapted to be received within a pocket 39 which is attached to the rear side of the elementwhich it is desired to attach to the arm. such element being the ordinary semaphore shown in Fig. 6. for the arms 2! and 24 of Figs. 7 and 9 respec tively.

Sections 31 and II lie in a plane parallel to the surface of the poster and at right angles to shaft II. The outer end of section I. is bent parallel with the hub 36 as indicated at ll so as to engage the inner edge 42 of pocket I! and thus prevent this edge from coming in contact with the hub or interfering with the oscillation. For the same purpose the wire forming the arm, as it leaves the hub portion II is bent into a hump II, shownin Fig. 4. Pocket I! may conveniently be made by stapling or otherwise securing a piece of pasteboard or cloth M to the rear surface of the semaphore. the stapling being located at the sides of thestripasindicatedatli.

The oscillator has a single radial arm ll and a pair of curved armature portions 41 and 48. Each of these extends in semi-circular form from the outer or lower end of the radial arm I. The

. ans-n upper ends of the armature portion do not quite meet, thus leaving a short gap between them. At

itslnnerendtheradialarmliisfixedtoshaft 33, as, for example, by means of a screw 49, so that the oscillator drives or turns the shaft together with supporting arm 22, and whatever device is mounted upon it.

Solenoid II of a coil of a large number of turns of fine wire which has sumcient resist ance to be operated from the mains of the ordinary lighting circuit without overheating and without drawing more than a fraction of an ampere of current from the main. In the form of the invention shown in Figs. 1, 2 and 3, the cir cuit through the solenoid II is opened and closed by external means such for example as a thermostatically controlled switch, a circuit interrupter operated by clock work, or any convenient form of switch which is adapted to open and close the circuit periodically.

In the accompanying drawings a thermostatically actuated switch 50 is shown. This switch is provided with prong contacts ii which are adapted to be inserted in the usual electrical outlet or connector. A connectionplug 52 which is attached to the end of the conductors 32 is similarly connected to the side of the thermostatic switch 50. Switch 50 contains a bi-metallic thermostatic strip 53 (see connection diagram shown in Fig. 1a), which, when heated by a small coil 54 surrounding it causes contacts 55 to close thereby short-circuiting coil Bl. Hence when the strip it cools oi! due to the cessation of current through coil 54, contacts 55 again open. It will be understood that contacts Stare in series with the circuit through one of the contact prongs iii and solenoid 2| and thereby cause an intermittent variation in the current through the solenoid. This variation amounts to a periodic cutoil of the current through the solenoid since the resistance of heating coil 54 is so high that the amount of current which passes when it is in circult is negligible.

' position to the left of the centre line. These positions, however, are only illustrative, and solenoid 2| may be placed in almost any desired position from a point just off of the centre line at the top to a point a few degrees from the centre line at the bottom, depending upon the length of swing or oscillation and the character of movement desired. Such shifting of the solenoid II to the right or'to the left, in addition to varying the length of swing and character of movement, also compensates for the displacement of the oscillator to the right or left of a central position caused by the weight of the semaphore 23 or movable arm 24.

It is well understood that when a movable magnetizable core is so mounted that it is free to be drawn into a coil through which a current of electricity is passing that the core will advance until the magnetic centre thereof coincides with the magnetic centre of the coil. Assuming that soilenoid II is in the dotted position A and that a current is established through the coil by means of the thermostatic switch 50, armature 48 will commence to move into the solenoid until the magnetic centre of armatures ll and ll, which opposite the end of radial arm 48 is as close as possible to the centre of solenoid II. The result is that am is raised to the right in Fig. 1 until it strikes or approaches very close to the solenoid.

Then if the current through the coil is interrupted by switch 50, the weight of arm 48 which is .sumcient to overbalance the weight of the supporting arm 22 and the semaphore carried thereby, will cause the oscillator 20 to swingin appropriate to the particular scene on the poster.

It will be observed that the armature portions 41 and 4B of the oscillator are not of uniform cross-section but that the cross-sectional area of these armatures increases towards the bottom. We have found that by constructing the armatures in this manner so that their cross-sectional areas increase as they are drawn farther and farther into the solenoid, that the torque is renof electromotor shown in Figs. 9 and 10 is about the same as that previously described. The dif- 'ferences lie in the fact that the switch for controlling the circuit of the solenoid is actuated by the movement of the oscillator, and the oscillator itself is of a particular construction.

The solenoid 2| is mounted as before upon an adjustable arm 30' which is supported upon the poster sheet 25' in the same manner as previously described in connection with arm 30.

Mounted upon the radial arm 56 of the oscillator Ill is a mercury switch 58 which consists of a glass envelope into the bottom of which two electrodes 59 and 60 are sealed, these electrodes being" electrically connected by a drop of mercury iii in certain angular positions of the switch.

Current is supplied to the device through the cable 62, one conductor of, which leads directly to solenoid 2|, and the other conductor of which leads to one of the electrodes of the mercury switch 58. The other electrode is connected with coil 2i so that switch 58 is connected in series with this coil.

In Fig. 9 the coil 2| has been shifted oi! center to one of its operative positions. It cable 62 is connected to a source of current, armature II will be drawn into the solenoid. The torque produced by coil ll is ordinarily sufllcient to draw the armature only partway into the solenoid, and not sumcient to overcome the overbalanced weight of the oscillator 51, the center of which is approx.- imately at the point W near the bottom of the oscillator. rotating the point W to either the left or the right up to a position near coilli'. the torque is sufficient to maintain the device oscillating at full swing or amplitude.

If the oscillator is set in motion by The mercy switch is so constructed that the contacts 50 and I are closed by the mercury while the centre of weight W swings between a predetermined angle on each side of the vertical centre line of motion. Thus, for example, assuming that the centre of weight W is at the top of its stroke adJacent the right hand side of coil 2|, the oscillator rotates by gravity as.

the point W descends to about the point C, when the mercury switch closes. The inertia of the oscillator and parts moving therewith, however,

is suiiicient to overcome the opposing torque of coil 2l'- and the clockwise rotation of the oscillator continues until'the upper end 08 of armae ture 41' comes within the influence of coil II.

The torque produced by the coil from that point on aids in maintaining the clockwise rotation of the oscillator and imparts sufficient additional energy to the same to carry the centre of weight W up to a position close to the left hand side of coil II, the current through'the solenoid however being cut oil by switch 5. when the point W passes approximately the point D on the upward stroke.

A repetition of the events just described now takes place while the oscillator rotates in the opposite or counter-clockwise direction to the position at which it started at the righthand side of coil 2!. This completes a full cycle of operation.

- The mercury switch 58 is a convenient form of switch to use since it may be easily attached to the oscillator by means of the clip 64. Moreover, it is inexpensive and as its only moving part is the drop of mercury I, there is nothing about the switch to get out of order. It will be understood however, that a mechanical switch or any other convenient form of switch adapted to open and close thecircuit through the solenoid 2| during the oscillation of oscillator 51 may be used in place of the mercury switch.

The points C and- Dat which the circuit is opened and closed by switch 58 may be shifted either up or down but their exact location is not important.

The structure of oscillator SIused in the form of our electromotor shown in Figs. 9 and 10, is such as to provide for quick and easy assembly of the electromotor. The oscillator consists of two parts 65 and 66. Each of these parts is exactly alike and is of equal weight. Part 65 comprises armature 41 and radial bar 61 which extends from the lowerend of armature 41' toward the upper end. Part 66 consists of armature ll and a similar radial bar It. .-The two parts 65 and 66 are pivoted together by means of a small bolt or rivet 69, the bars 61 and I crossing one another so that movement of the armatures .41 and 48' toward one another will tend to separate bars 61 and 6s.

Bars 61 and BI constitute the radial arm 56 and are firmly secured together at their upper end by any suitable means, such for example as a bolt Ill. Theinterior surfaces of the ,bars 61 and 68 are'nicked crosswise as indicated at H at the centre of the oscillator so as to position the oscillator on the electromotor shaft ll.

The clamping action of the bars 81 and 6! drawn together by the bolt III holds the oscillator in position on the shaft. The resiliency of these bars is high and the clamping pressure 4 sure pressurecanbereadiiyexertedtosprlngthe arms 01 and II to release than from shaft II. This motion brings the ends ll of armature 41' close to. or into contact with. the corresponding 5 end of armature ll. The normal gap between these ends, however. is small enough so that they act as a stop definitely limiting the motion which can be thus produced so that the oscillator can bemade of cast iron without danger of breakage I. when manipulating it as just described.

In this form of electromotor the oscillator can be so readily assembled upon and removed from shaft 33 that it is not necessary to provide for a means of disconnecting the supporting arm I! II for the semaphore, and this arm is preferably made integral with shaft ll as shown.

Referring now to the modified form of electrov motor of Fig. ,ll,'this form'is similar to that shown in Fig. l, in that it is controlled by an I external switch such as a. thermostatic switch II. It is adapted ,particularly for actuating advertising devices where it is necessary to arrange the electromotor shaft in vertical pomtion instead of horizontally.

II The solenoid 2|" is similar to solenoid II and similarly mounted. Only a single armature 12 is employed and the restoring force is produced by means of a spiral spring ll instead of by gravity as in the other forms of electromoto'r.-

' The manner in which these parts are-associated however, is such as to impart a particularand somewhat diii'erent motion to the animated element of the-display.

The animated element is mounted upon an ll armllsimilartoarmn. Thisarmismounted upon a vertical shaft 16 which is similar toshaft II but is mounted in'vertical position in a hearing bushing '16 which is in turn fixed in an aperture in a horizontal portion ll of the display device. On the lower end of bushing 18 the inner end ofspring 'llisfixedlysecuredas forexample by means of a nut II. The outer end of spring li isfixedtoaradialbarltwhichisfixe'dto the lower end of shaft to turn thesame. The.

a movement of the shaft is thereby dependent upon the motion imparted to the outer end of spring If. A secondbar ll projects from a hub ll which is loosely mountedon the outer end of shaft II, and below this baris a collar II is secured upon shaft II by means of a set screw it so as to retain hub ll upon the shaft,

Thearmature 'llissecur'edfirmlytotheouter end of bar ll, which'serves asits support,and a finger l4 projects upwardly from bar I and is.

.55 securedtooneoftheinnerturnsofspiralspring II. when armature I2 is'drawn into coil 2|", motion is thereby imparted to the inner coil of the spring to which finger II is attached. This causes a movement of the outer convolutions of m the spring and consequently of bar I! and shaft II. The rotation of shaft ll will be greater, however, than the rotation of armature If, and, moreover, as the armature II oscillates under the influence of the solenoid and the inner portion 05 0fthespring,themoti0n0ftheshaft'll andthe animated element actuated thereby will be modified by the resilient connection between bar ll andbar'llconsistingoftheouterportionof spiral spring ll I0 Our improved electromotor has proved itself to beextremelypracticableforuseinactuatingadvertising devices and for operation on either' alternating or direct current. In operating such a device upon alternating. current it is diihcult I to prevent a chattering or hum which isflcaused angles to' and spaced from the axis of said shaft,

of our invention, and that the construction of the 10 electromotor may be varied within the scope of the appended claims without departing from the invention. I V I We claim:

' 1. An electromotor comprising a solenoid, an it oscillator, means for supporting said oscillator within the influence of the solenoid to permit oscillation of the oscillator about'its centre,'a thermostatically actuated switch for intermittently opening and closing the circuit through the sole- 20 noid, and means for restoring the oscillator to its original position after each movement thereof by the solenoid, the period of operation of said switch difiering slightly from the natural period of oscillation of the oscillator so as to cause successive swings of the oscillator to difier. slightly from each other and produce a slowly recurring sequence of oscillations.

2. In an electromotor, a solenoid, an oscillator comprising a pair 'of substantially semi-circular armatures, means for supporting said oscillator so as to allow said armatures to oscillate freely through said solenoid, means providing a restoring force to withdraw said armature from within the solenoid. and a switch for opening and clos- 38 mg the circuit of the solenoid actuated by said oscillator to maintain the circuit" closed during a predetermined portion of the swing of the 0s cillato'r on one side of the centre of the swing.

3. An electromotor comprising an oscillator, 40 vmeans for supporting the same, a solenoid having its axis at right angles to and spaced from the axis of oscillation of the oscillator, said oscillator having a substantially ring-shaped armature coacting with the solenoid, means for intermittently opening and closing the circuit of said solenoid to cause movement of the armature in one direction, and means for producing a restoring force to cause movement of the armature in the opposite direction during the periods wh the solenoid circuit is open.

4. An electromotor comprising a shaft, a hearing therefore, a support for thejbearlng, a member pivotally mounted upon said support, a solenoid carried by said member with its axis at right an oscillator mounted upon said shaft having a curved armature portion adapted to be drawn into'said solenoid, means for intermittently enerdriven element.

6. In an electromotor, a solenoid, an armature, a driven element. a spiral spring, means for operatively connecting the I armature to an inner coil of said spiral spring, and means for operatively connecting the driven element to an coil of said spiral spring so as to cause the movement imparted thereto to be greater than and a variation ofv the movement of the armature.

7. In an electromotor, a solenoid, an oscillator therefor, and a shaft for rotatably supporting said oscillator, said oscillator comprising a pair of semi-circular armatures hinged together at one end and each having an arm extending inwardly from said hinge, and means for holding said arms together at their inner ends thus causing said arms to clamp onto said shaft, said arms being sufflciently resilient to permit springing thereof to release them. from or apply them to said shaft.

8. In an electromotor, a solenoid, an oscillator comprising a pair of substantially semi-circular armatures joined together at one end and extending into close proximity at their opposite ends, said armatures being'adapted to enter the solenoid from'opp'osite sides and means for supporting said oscillators to oscillate freely through said solenoid.

9. In an electromotor, a solenoid, an oscillator comprising a pair ofsubstantially semi-circular tapered armatures, said armatures being adapted to enter the solenoid from opposite sides, means for supporting said oscillator so as to allow said tapered armatures to oscillate freely through said solenoid and means for intermittently opening and closing the circuit through the-solenoid.

10. An electromotor comprising a solenoid, an oscillator mounted to freely oscillate through the solenoid, said oscillator of itself seeking a definite angular position relative to the solenoid, counterbalancing means for causing the oscillator to assume a diiferent angular position relative to the solenoid and means for adjusting the positions of the solenoid and oscillator relative to another.

.11. An electromotor comprising an adiustably mounted solenoid, an oscillator mounted to freely oscillate through the solenoid, said oscillator of itself seeking a definite angular pos'itionrelative to the solenoid, counterbalancing means for causing the oscillator to assume a different angular position relative to the solenoid and means for adjusting the positions of the solenoid and oscillator relative to one another.

12. In an; animated advertising device, the combination of a display poster containing a scene having a stationary portion and a movable portion including a display arm, a pivoting sup- I port therefor, means for balancing the display arminthe correctangularpositiontosuitthe stationary portion of said scene including a pendulum carried by said pivoting support having a sector-shaped armature, the'balanced positionofsaidpendulumandarmaturebeingdsone pendent on the arrangement of the display arm for the particular scene, means to impart to said display arm an oscillatory movement comprising said pendulum, a solenoid to cooperate with said armature, means for mounting the solenoid on the display poster to suit said balanced position of the armature while permitting the armature to oscillate freely therethrough, and means for intermittently opening and closing the circuit through said solenoid to cause said pendulum and said display arm to oscillate.

13. In an animated advertising device, the combination of a display poster containing a scene having a stationary portion and a movable portion including a display arm, a pivoting support therefor, means for balancing the display arm in the correct angular position to suit the stationary portion of said scene including a pendulum carried by said pivoting support having a sector-shaped substantially semi-circular armature, the balanced position of said pendulum and armature being dependent on-the arrangementof the display arm for the particular scene, means to impart to said display arm an oscillatory movement comprising said pendulum, a solenoid to cooperate with said armature, means for mounting the solenoid on the display poster to suit said balanced position of'the armature while permitting the. armature to oscillate freely therethrough, and means for intermittently opening and closing the circuit through said solenoid to causesaid pendulum and-said display arm to oscillate.

14. In an animated advertising device, the combination of a display poster containing a scene having a stationary portion and a movable portion including port therefor, means for balancing the display arm in the correct angular position to suit the stationary portion of said scene including a pendulum and a sector-shaped armature connected to the display arm to provide a freely swinging the balanced position of said pendulum and armature being dependent on the arrangement of the display arm for the particular scene. means to impart to said display arm an oscillatory movement comprising a solenoid to cooperate with said pendulum and armature, means a display arm, a pivoting sup-' for. mounting the solenoid on the display poster to suit said balanced position of the armature while permitting the armature to oscillate freely therethrough, and means for intermittently closingandopeningthecircuitthroughsaidsolenoid to cause said pendulum and saiddisplay arm tooscillate.

' IL! I. GREGORY. HI NBY EMERSON OOIDNGB. 

